The National Surgical Adjuvant Breast and Bowel Project (NSABP) is an NCI-funded clinical trials cooperative group for cancer treatment and prevention and control research. The group has a more than 40- year history of conducting large-scale controlled treatment trials that have improved the treatment of patients with breast or colorectal cancer and have provided a better understanding of tumor biology. In 1992, the MSABP extended its research agenda to include cancer prevention trials. The NSABP has been a CCOP Research Base since the inception of the CCOP Program and 60 CCOPs currently list the NSABP among their research bases. CCOP participation in NSABP treatment and prevention trials is substantial; approximately 33% of NSABP accrual is attributable to CCOP investigators. This application requests continued funding for the NSABP to continue as a CCOP Research Base for the period June 1, 2007, through May 31, 2012. During the proposed grant period, the NSABP will: 1) continue to design and implement multi-institutional cancer treatment and prevention and control clinical trials; 2) analyze, report, and publish the results of current NSABP studies; 3) implement recruitment mechanisms and procedures to achieve adequate accrual and foster the participation of women and minorities in NSABP clinical trials; 4) maintain data collection, data monitoring, and quality control procedures that are in compliance with federal guidelines; 5) monitor CCOP performance through ongoing quality assurance programs; and, 6) continue the integration of CCOP investigators into the overall functioning of the NSABP.